Electrical-conduit construction



SePt- 24 l929- B. o. WIDELL 1,729,315

ELECTRICAL CONDUTA CONSTRUCTION Filed oct. 17, 1928 Patented Sept. 24, 1929 UNITED STATES PATENT ossics BERNARD 0. WIDELL, OF WEST HARTFORD, CONNECTICUT, ASSIGNOIR TO THE WIRE- MOLD COMPANY, OF HARTFORD, CONNECTICUT, .Z-l. CORPORATION OF CONNECTCUT ELECTRTCAL-CONDUIT CONSTRUCTION Application led October 17, 1928.

This invention relates to the construction the of Surface wire conduits of the type composed of fiat or substantially flat base strips and channel shaped covers that are applied to the base strips in such manner as to form a continuous unobstructed raceway in which the wires are concealed, and it is more particularly concerned with the construction of the parts which are supplied for the purpose of continuing the conduit over a beam or around a post or a similar projection from the surface on which the running lengths are fastened.

Prior to this invention the running lengths of conduit comprising the assembled bases and covers were ended near the beam and short assembled base and cover pieces of the required lengths, depending on the size of the beam, were fastened to the sides and bottom 2o of the beam. With these parts in place the wires were pulled through one running length and then pushed separately through the completed tubular lengths fastened to the side, bottom and side of the beam, and finally pushed or pulled through the other running length of the conduit, after which internal and external elbow caps were snapped upon the parts at the several corners. This, owing to the necessity of threading the wires through the closed tubular sections around the beam and also to th-e small angular spaces at the internal corners, was a laborious and expensive operation, especially with long wires, as it took considerable time and incurred much bending and looping of the wires to thus get them about the beam and into the running lengths of the conduit.

The object of the present invention is to provide a` construction which in a simple and cheap way eliminates the disadvantages of prior constructions. This is attained by so forming the beam base strip that it may be fastened about the beam and the wires between the ends of the running lengths merely laid over the base strip, the cover pieces of the right length being subsequently slipped longitudinally into place on and caused to grip the base strip on the sides and bottom of the beam, and then the elbows applied at the corners to close the openings and complete Serial No. 313,009.

conduit, thereby obviating the necessity of threading the wires through separate tubular sections with the incident bending of the wires and the difiicultyof doing this in confined spaces.

In the accompanying drawing Fig. 1 shows a side view of a conduit that embodies this invention passed around a beam fastened to a ceiling. Fig. 2 is a similar view with the internal and external elbow caps and the conduit covers on the sides and bottom of the beam omitted, and showing the wires laid over the conduit base strips.V Fig. 3 is a view looking up at the beam showing the conduit A base strips applied thereto. Fig. 4 is a section on the dotted line 4-4 on Fig. 1. Fig. 5 isa section on the plane indicated by the dotted line 5-5 on Fig. l. Fig. 6 is a'view of a corner of one form ofthe beam base strip. Fig. 7 is a view of a corner of a modified form of beam base strip. Fig. 8 is a View of a corner of another modification of the beam base strip. Fig. Slis a plan showing a way the beam base strip may be made.

'In the views 1 indicates the ceiling and 2 a beam extending therefrom. The running lengths of the conduit are fastened to the ceiling with their ends 3 and 4 adjacent to the beam and connected with the base strips 5 and 6 of the internal elbows in the usual manner.

In the preferred form a yoke shaped base strip 7 is fastened to the beam so as to extend across the bottom vand up the sides. The main portions 8 of this base strip areof such a width that they will fit within and be grasped by the outwardly and inwardly curved edges 9 of the cover channel-shaped pieces of the conduit that are subsequently applied thereto. Other portions 10 of this strip are reduced in transverse sections to a width that is narrower than the space between the inwardly curved edges of the cover pieces.

Instead of forming elongated reduced sections, as shown in Fig. 6, for narrowing portions of the base strip, notches 11, as seen in Fig. 7, can be made at intervals in the edges of the base strip. These reduced portions whether elongated, or in the form of notches, are so located that they will come at the angles where the strip is bent about the corners of the beam, and they are preferably made of such a length that the base strip may be used with beams of different sizes and have the corner bends of the strip at the narrow sections. In other words, the cross-sections of the base strip at the corners and on each side near the corners of the beam are narrower than the main portions of the strip that eX- tend across the bottom and on the sides of the beam. The beam base strip may if desired be made of several pieces, comprising external angular corner pieces l2, which may be notched, and straight bottom and side pieces 13, as illustrated in Fig. 8, but it is preferred to have the beam base strip made in one piece with elongated narrow portions.

Perforations 14 are made in the beam base strip for the fastening screws, and it is preferred to have the metal about the perforations depressed so that the depressed portions will retain the main portion of the base strip a slight distance away from the beam, in order that the cover pieces may be readily slipped on the base strip. If desired the beam base strip may be made of indefinite length and scored at intervals and perforated at different localities as illustrated in Fig. 9 so that the strip may be readily adapted to the particular size of beam which is encountered.

When a base strip embodying this invention is fastened to the beam with the narrbw portions or notches at the corners the circuit wires 15 are drawn from the end of one of the running lines of the covered conduit 3 and merely laid over the base strip and drawn through the other running line of the conduit 4. It is unnecessary with the construction described to thread the wires through any tubular parts attached to the beam. With the wires extending from one running length of the conduit to the other and merely laid over the base strip, the channel-shaped cover pieces 16, 17, are slipped longitudinallyl up on the sides of the beam and the cover piece 18 is slipped longitudinally across the bottom of the beam, the curved edges of these pieces being engaged with the wider sections of the base strip when so applied. This is possible with the constructions set forth as the narrower sections or notches of the base strip at the corners permit the cover pieces to be thus slid on longitudinally and engaged with the wider sections of the base strip. After the side and bottom channel shaped cover pieces have been slid into position in this manner the internal elbow covers 19, 20, are snapped in place so as to overlie the ends of the running sections and also the ends of the cover pieces on the sides of the beam, and the external angular cover pieces 21, 22, are snapped in place so as to overlie the ends of the cover pieces on the sides and bottom of the beam. It is a requisite of practice that the base pieces of a conduit of this character be firmly mechanically engaged so as to provide a continuous ground for the installation in case of short-circuit, and when the side cover pieces are applied to the beam base strip in the man ner described, they clamp together the ends of the internal elbow base pieces and the ends of the beam base strip as illustrated in Fig. 4.

By notching or reducing the width of the beam base strip where it bends around the corners of the beam it is possible to slip the channel-shaped conduit cover pieces in place over the continuons wires which are in final position about the beam and engage the cover pieces with the base pieces, and thus obviate all necessity of threading the wires through tubular parts applied to the beam, which without entailing any additional cost in the production of the elements results in a considerable saving of time and labor for installation.

The invention claimed is:

l. A surface conduit for enclosing electrical wires over a beam, comprising a yokeshaped base strip adapted to be fastened to a beam so as to extend across the bottom and up the sides of the beam, said base strip having sections of reduced width at the angles which are to fit about the corners of the beam, and channel-shaped cover pieces having their edges shaped to freely slide longitudinally over the narrowed sections of the base strip and to lit and grip the wide sections of the base strip.

2. A surface conduit for enclosing electrical wires over a beam, comprising a yokeshaped base strip adapted to be fastened to a beam so as to extend across the bottom and up the sides of the beam, said base strip having notches at the angles which are to fit about the corners of the beam, and channel-shaped cover pieces having their edges shaped to freely slide longitudinally through the notched sections of the base strip and to closely fit and grip the main sections of the base strip.

3. A surface conduit for enclosing electrical wires over a beam, comprising a yokeshaped base strip, said base strip having sections of reduced width at the angles which are to fit the corners of the beam and main sections adapted to be fastened to the bottom and sides of the beam, and channel-shaped cover pieces having their edges shaped to freely slide longitudinally over said reduced corner sections and to closely fit and gripl the main sections of the base strip.

4. A surface conduit for enclosing electrical wires over a beam, comprising a yokeshaped base strip adapted to be fastened to a beam so as to extend across the bottom and up the sides of the beam, said base strip having` sections of reduced width at the angles which are to fit about the corners of the beam and depressed perforations for the fastening means, and channel-shaped cover pieces hav-.

ing their edges shaped to freely slide longitudinally over the narrowed sections of the base strip and to closely t and grip the Wide sections of the base strip.

5. A surface conduit for enclosing electrical Wires. over a beam, which comprises a base having a section adapted to be fastened to the bottom of the beam, sections adapted to be fastened to the sides of the beam and sections fitting the corners of the beam, said corner sections being of reduced Width at the angles, and channel shaped cover ieces having their edges formed to slide fieely over said reduced portions and to closely it and grasp the Wider portions of the base sections.

6. A surface conduit for enclosing electric-al Wires over a beam, which comprises a base having a section adapted to be fastened to the bottom of the beam, sections adapted to be fastened to the sides of the beam and sections itting the corners of the beam, said corner sections being of reduced Width at the angles, channel shaped cover pieces having their edges formed to slide freely over said reduced portions and to closely fit and grasp the Wider portions of the base sections, and channel shaped elbow sections snapped in place so as to overlie the ends of said cover sections.

BERNARD O. WIDELL. 

